Lifting-jack.



4 un., 704,683. Patented July l5, |902.

J. HnPPl.

LIFTING JACK.

(Application filgd Nov. 27, 1900.)

70mm w UNrTn STATES PATENT OFFICE.

JOHANN HPPI, OF RMLANG, NEAR ZURICH, SWITZERLAND.

LiFTlNG-JACK.

SPECIFICATION forming partrot Letters Patent No. 704,683, dated July 15, 1902.

Application filed November' 27, 1900. Serial No. 37,921. (No model.)

To all whom t 71mg/ concern: Y

Beit known that I, JOHANNHPPI, a citizen of the Republic of Switzerland,residing at Rmlang, near Zurich, Switzerland, (whose post-office address is Sawworks, Rmlang, near Zurich, Switzerland,) have invented new and useful Improvements in Lifting-Jacks, (for which I have made application for patents in Austria, dated September 14, 1900; in Germany, dated September 14, 1900; in Italy, dated November 2, 1900; in France, dated November 3, 1900, and in Great Britain, dated November 3, 1900, No. 29,728,) of which the following is a specification.

My invention relates to improvements in lifting-jacks, and has for its object to provide means whereby the lift of such jacks is increased. I attain this object by the mechanism illustrated in the accompanying drawings, in which- Y Figure l is a vertical section at line A A of Fig. 3; Fig. 2, a front View, and Fig. 3a cro-ss- -section at line B B of Fig. l, of myimproved liftingjack.

Similarletters referto similarparts throughout the several views.

In the body a of the jack are mounted the spur-pinions b and o, the spur-wheel d, and the crank-handle e, by means of which the rack g, furnished with a foot f, can be raised and lowered. In the said rack a lifting-bar Y h is rendered longitudinally movable, having secured to its lower end t' a chain 7c or the like iexible connection. This chain is guided in grooves Z, formedin the rack g, and runs over a wheel m, mounted in the latter, while its other end is secured to the body of the jack. In turning the handle e, and thereby raising the rack g and with it the chain-wheel m a certain distance, the distance from the center of the chain-wheel m to the lower end of the body of the jack will increase, and as Comparing my improved lifting-jack with such as have hitherto been inuse and assuming that they are geared at the same ratio and the number of turns imparted to the crank-handle is the same, in my invention the speed at which the lifting-bar moves is doubled, while the lift of the rack is less half that of the lift and the speed of the liftingbar, so thatV when applying the said bar to the load the latter will be raised quicker and greater power required, while when applying the footfof'thesaid rack the load will be raised slower and less power required, so that it is preferable to raise light loads by the said bar and heavy loads by the said rack.

Vhat I claim as my invention, and desire to secure by Letters Patent, is-

In a lifting-jack, the jack-body a, the rack g and the bar 7L adapted to slide in each other,

the pulley mmounted upon the top of the said rack andthe chain Z passing over the said pulley'and having one end secured to the lower endof the said bar and the other end to the-lower end of the said body, the pinion c `mountedin the body a in gear with the said rack and means for rotating the said pinion by hand, all combined substantially as and W'itnesses A. LIEBERKNECHT, FRITZ LAUENER. 

